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BSD 4_3_Net_2 development
[unix-history] / .ref-8c8a5b54e79564c14fc7a2823a21a8f048449bcf / usr / src / sys / vm / vm_glue.c
/*
* Copyright (c) 1987 Carnegie-Mellon University
* Copyright (c) 1991 Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* The CMU software License Agreement specifies the terms and conditions
* for use and redistribution.
*
* @(#)vm_glue.c 7.1 (Berkeley) %G%
*/
#include "param.h"
#include "systm.h"
#include "user.h"
#include "proc.h"
#include "buf.h"
#include "../vm/vm_param.h"
#include "../vm/vm_map.h"
#include "../vm/vm_page.h"
#include "../vm/vm_kern.h"
int avefree = 0; /* XXX */
unsigned maxdmap = MAXDSIZ; /* XXX */
kernacc(addr, len, rw)
caddr_t addr;
int len, rw;
{
boolean_t rv;
vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE;
rv = vm_map_check_protection(kernel_map, trunc_page(addr),
round_page(addr+len-1), prot);
return(rv == TRUE);
}
useracc(addr, len, rw)
caddr_t addr;
int len, rw;
{
boolean_t rv;
vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE;
rv = vm_map_check_protection(u.u_procp->p_map, trunc_page(addr),
round_page(addr+len-1), prot);
return(rv == TRUE);
}
#ifdef KGDB
/*
* Change protections on kernel pages from addr to addr+size
* (presumably so debugger can plant a breakpoint).
* All addresses are assumed to reside in the Sysmap,
*/
chgkprot(addr, len, rw)
register caddr_t addr;
int len, rw;
{
vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE;
vm_map_protect(kernel_map, trunc_page(addr),
round_page(addr+len-1), prot, FALSE);
}
#endif
vslock(addr, len)
caddr_t addr;
u_int len;
{
vm_map_pageable(u.u_procp->p_map, trunc_page(addr),
round_page(addr+len-1), FALSE);
}
vsunlock(addr, len, dirtied)
caddr_t addr;
u_int len;
int dirtied;
{
#ifdef lint
dirtied++;
#endif lint
vm_map_pageable(u.u_procp->p_map, trunc_page(addr),
round_page(addr+len-1), TRUE);
}
procdup(p, isvfork)
register struct proc *p;
int isvfork;
{
register struct user *up;
vm_offset_t addr;
vm_size_t size;
#if 0
/*
* Duplicate the process address space.
* XXX if this is a vfork we arrange to share data/stack to
* preserve brain-dead semantics of vfork().
* XXX this doesn't work due to a bug in the VM code.
* Once a process has done a vfork setting up sharing maps,
* any future forks may fail as the source VM range doesn't
* properly get write-protected. This causes the parent to
* not create copies and instead modifies the originals.
* If the parent activates before the child, the child will
* get a corrupted address space.
*/
if (isvfork) {
addr = trunc_page(u.u_daddr);
size = ctob(u.u_dsize);
(void) vm_map_inherit(u.u_procp->p_map, addr,
addr + size, VM_INHERIT_SHARE);
(void) vm_map_inherit(u.u_procp->p_map, u.u_maxsaddr,
VM_MAX_ADDRESS, VM_INHERIT_SHARE);
}
#endif
p->p_map = vm_map_fork(u.u_procp->p_map);
#if 0
if (isvfork) {
(void) vm_map_inherit(u.u_procp->p_map, addr,
addr + size, VM_INHERIT_COPY);
(void) vm_map_inherit(u.u_procp->p_map, u.u_maxsaddr,
VM_MAX_ADDRESS, VM_INHERIT_COPY);
}
#endif
/*
* Allocate a wired-down (for now) u-area for the process
*/
size = round_page(ctob(UPAGES));
addr = kmem_alloc_pageable(kernel_map, size);
vm_map_pageable(kernel_map, addr, addr+size, FALSE);
p->p_addr = (caddr_t)addr;
up = (struct user *)addr;
/*
* Update the current u-area and copy it to the new one
*/
resume(pcbb(u.u_procp));
bcopy(u.u_procp->p_addr, p->p_addr, size);
up->u_procp = p;
PMAP_ACTIVATE(p->p_map->pmap, (struct pcb *)p->p_addr);
/*
* Arrange for a non-local goto when the new process
* is started, to resume here, returning nonzero from setjmp.
*/
up->u_pcb.pcb_sswap = (int *)&u.u_ssave;
if (savectx(&up->u_ssave)) {
/*
* Return 1 in child.
*/
return (1);
}
/*
* Clear vm statistics of new process.
*/
bzero((caddr_t)&up->u_ru, sizeof (struct rusage));
bzero((caddr_t)&up->u_cru, sizeof (struct rusage));
up->u_outime = 0;
return (0);
}
/*
* XXX Scaled down version from vm_page.c
*/
vminit()
{
/*
* Set up the initial limits on process VM.
* Set the maximum resident set size to be all
* of (reasonably) available memory. This causes
* any single, large process to start random page
* replacement once it fills memory.
*/
u.u_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ;
u.u_rlimit[RLIMIT_STACK].rlim_max = MAXSSIZ;
u.u_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ;
u.u_rlimit[RLIMIT_DATA].rlim_max = MAXDSIZ;
u.u_rlimit[RLIMIT_RSS].rlim_cur = u.u_rlimit[RLIMIT_RSS].rlim_max =
ptoa(vm_page_free_count);
proc[0].p_maxrss = vm_page_free_count;
}
#include "../vm/vm_pageout.h"
#ifdef DEBUG
int enableswap = 1;
int swapdebug = 0;
#define SDB_FOLLOW 1
#define SDB_SWAPIN 2
#define SDB_SWAPOUT 4
#endif
/*
* Brutally simple:
* 1. Attempt to swapin every swaped-out, runnable process in
* order of priority.
* 2. If not enough memory, wake the pageout daemon and let it
* clear some space.
*/
sched()
{
register struct proc *rp;
register int rppri;
struct proc *inp;
int inpri;
vm_offset_t addr;
vm_size_t size;
loop:
#ifdef DEBUG
if (!enableswap) {
inp = NULL;
goto noswap;
}
#endif
wantin = 0;
inp = NULL;
inpri = -20000;
for (rp = allproc; rp != NULL; rp = rp->p_nxt)
if (rp->p_stat == SRUN && (rp->p_flag & SLOAD) == 0) {
rppri = rp->p_time +
rp->p_slptime - (rp->p_nice-NZERO)*8;
if (rppri > inpri) {
inp = rp;
inpri = rppri;
}
}
#ifdef DEBUG
if (swapdebug & SDB_FOLLOW)
printf("sched: running, procp %x pri %d\n", inp, inpri);
noswap:
#endif
/*
* Nothing to do, back to sleep
*/
if ((rp = inp) == NULL) {
(void) splhigh();
runout++;
sleep((caddr_t)&runout, PVM);
(void) spl0();
goto loop;
}
/*
* We would like to bring someone in.
* This part is really bogus cuz we could deadlock on memory
* despite our feeble check.
*/
size = round_page(ctob(UPAGES));
addr = (vm_offset_t) rp->p_addr;
if (vm_page_free_count > atop(size)) {
#ifdef DEBUG
if (swapdebug & SDB_SWAPIN)
printf("swapin: pid %d(%s)@%x, pri %d free %d\n",
rp->p_pid, rp->p_comm, rp->p_addr,
inpri, vm_page_free_count);
#endif
vm_map_pageable(kernel_map, addr, addr+size, FALSE);
(void) splclock();
if (rp->p_stat == SRUN)
setrq(rp);
rp->p_flag |= SLOAD;
(void) spl0();
rp->p_time = 0;
goto loop;
}
/*
* Not enough memory, jab the pageout daemon and wait til the
* coast is clear.
*/
#ifdef DEBUG
if (swapdebug & SDB_FOLLOW)
printf("sched: no room for pid %d(%s), free %d\n",
rp->p_pid, rp->p_comm, vm_page_free_count);
#endif
(void) splhigh();
VM_WAIT;
(void) spl0();
#ifdef DEBUG
if (swapdebug & SDB_FOLLOW)
printf("sched: room again, free %d\n", vm_page_free_count);
#endif
goto loop;
}
#define swappable(p) \
(((p)->p_flag & (SSYS|SULOCK|SLOAD|SKEEP|SWEXIT|SPHYSIO)) == SLOAD)
/*
* Swapout is driven by the pageout daemon. Very simple, we find eligible
* procs and unwire their u-areas. We try to always "swap" at least one
* process in case we need the room for a swapin.
*/
swapout_threads()
{
register struct proc *rp;
struct proc *outp, *outp2;
int outpri, outpri2;
int didswap = 0;
extern int maxslp;
#ifdef DEBUG
if (!enableswap)
return;
#endif
outp = outp2 = NULL;
outpri = outpri2 = -20000;
for (rp = allproc; rp != NULL; rp = rp->p_nxt) {
if (!swappable(rp))
continue;
switch(rp->p_stat) {
case SRUN:
if (rp->p_slptime > outpri2) {
outp2 = rp;
outpri2 = rp->p_slptime;
}
continue;
case SSLEEP:
case SSTOP:
if (rp->p_slptime > maxslp) {
swapout(rp);
didswap++;
} else if (rp->p_slptime > outpri) {
outp = rp;
outpri = rp->p_slptime;
}
continue;
}
}
/*
* If we didn't get rid of any real duds, toss out the next most
* likely sleeping/stopped or running candidate. We only do this
* if we are real low on memory since we don't gain much by doing
* it (UPAGES pages).
*/
if (didswap == 0 &&
vm_page_free_count <= atop(round_page(ctob(UPAGES)))) {
if ((rp = outp) == 0)
rp = outp2;
#ifdef DEBUG
if (swapdebug & SDB_SWAPOUT)
printf("swapout_threads: no duds, try procp %x\n", rp);
#endif
if (rp)
swapout(rp);
}
}
swapout(p)
register struct proc *p;
{
vm_offset_t addr;
vm_size_t size;
#ifdef DEBUG
if (swapdebug & SDB_SWAPOUT)
printf("swapout: pid %d(%s)@%x, stat %x pri %d free %d\n",
p->p_pid, p->p_comm, p->p_addr, p->p_stat,
p->p_slptime, vm_page_free_count);
#endif
size = round_page(ctob(UPAGES));
addr = (vm_offset_t) p->p_addr;
vm_map_pageable(kernel_map, addr, addr+size, TRUE);
pmap_collect(vm_map_pmap(p->p_map));
(void) splhigh();
p->p_flag &= ~SLOAD;
if (p->p_stat == SRUN)
remrq(p);
(void) spl0();
p->p_time = 0;
}
/*
* The rest of these routines fake thread handling
*/
void
assert_wait(event, ruptible)
int event;
boolean_t ruptible;
{
#ifdef lint
ruptible++;
#endif
u.u_procp->p_thread = event;
}
void
thread_block()
{
int s = splhigh();
if (u.u_procp->p_thread)
sleep((caddr_t)u.u_procp->p_thread, PVM);
splx(s);
}
void
thread_sleep(event, lock, ruptible)
int event;
simple_lock_t lock;
boolean_t ruptible;
{
#ifdef lint
ruptible++;
#endif
int s = splhigh();
u.u_procp->p_thread = event;
simple_unlock(lock);
if (u.u_procp->p_thread)
sleep((caddr_t)u.u_procp->p_thread, PVM);
splx(s);
}
void
thread_wakeup(event)
int event;
{
int s = splhigh();
wakeup((caddr_t)event);
splx(s);
}
/*
* DEBUG stuff
*/
int indent = 0;
/*ARGSUSED2*/
iprintf(a, b, c, d, e, f, g, h)
char *a;
{
register int i;
for (i = indent; i > 0; ) {
if (i >= 8) {
putchar('\t', 1, (caddr_t)0);
i -= 8;
} else {
putchar(' ', 1, (caddr_t)0);
i--;
}
}
printf(a, b, c, d, e, f, g, h);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.